The ALPHA6 Aluminum Rings are the culmination of testing over hundreds of thousands of units fielded in some of the most unforgiving environments around the world. Through numerous iterations of intensive testing, SIG SAUER's proprietary aluminum alloy provides a highly durable ring system, while being ductile enough to form perfectly around the riflescope without damaging the maintube through proper installation. With the ideal balance of weight and strength, the ALPHA6 system is designed to excel in harsh conditions from the coastal flats to high mountain scree fields. FeaturesMachined from SIG SAUER's proprietary billet aluminum alloyType III flat black hard anodized finishBlack oxide hardened steel hardwareScope leveling tool only included with all mounts except 30mm Low